Spark-gap.



J. E. SEELEY.

SPARK GAP. APPLICATION FILED NOV. 30. 19:4.

1 ,1625659 Patented Nov. 30, 1915.

i i. I

ij K PATENT JAMES E. SEELEY, OE LOS ANGEIAES. CALIFORNIA, ASSIGNOR TO VULCAN COIL COMPANY, OF LOS ANGELES, CALIFORNIA, A CORPORATION OF CALIFORNIA.

SPARE? GAP.

Specification of Letters Patent.

Patented Nov. 30, 1915.

Application filed November 30, 1914. Serial No. 874,639.

which will operate over long periods without overheating and which will not deteriorate by continued use.

in spark gaps carrying a large current, such as is required in a heavy duty high tension machine, unless there is special provision made against overheating the spark gap apparatus will become excessively hot;

' and the metal of the terminal pieces will be- ,come so heated that arcing may melt the metal and destroythe terminals.

It is one of the objects of my invention to overcome these difliculties by providing a spark gap mechanism inwhich the discharge surfaces are kept in accurate parallelism with each. other to evenly distribute the dis charge over the surfaces; in which the discharge surfaces are long and narrow so as to allow ready access of air between the surfaces within the gap to keep the air in the gap as cool as possible; and in which there is sufficient means for radiating the heat from the terminal pieces. As a result of these features, my spark gap mechanism may be worked at its maximum capacityfor av long period without becoming so heatedthat the finger cannot be placed upon it; whereas the ordinary spark gap apparatus becomes excessively hot if operated for anylength of time. I makea practice of plac-- ing my spark gap apparatus n the ins de of the box or casing which contains my high tension electrical apparatus; the spark gap 'working so cool that it is possible to place it within the box without any detrimental effects.

In the accompanying drawings I have shown a. preferred form of my invention,

in which lra Wingsspark gap apparatus, Fig. 2 isa-n elevation of the same, and Fig. 3 is an elevation taken as indicated by line 33 of Fig. 1.

In the drawings the numeral may designate a case or box within which the spark gap may be placed; and 11 designates the base on which the apparatus is mounted. The apparatus embodies essentially a pair of terminals 12 preferably duplicates; one of which is supported on a rigidsupport 13 and the other of which is supported upon a. spring support 14:. This spring support 1-1 is of such nature as to allow movement of the one terminal back and forth toward the other terminal, in the direction indicated in Figs. 1 and 2. The springs, as hereinafter described. normally press the one terminal to 'ard the other terminal; and the termi-- nals are separated by manipulation of a small hand wheel 15 on the outside of the case. This hand wheel 15 connects with a.

sleeve 16 internally screw threaded and engaging the screw threaded bolt 17, which bolt is attached directly to the terminal supported by the spring support 11.

structed as illustrated in Figs. 1 and 3; embodying two parallel fiat springs20 secured to the base 11 at one end and carrying the terminal bracket 21 at their other ends.

Preferably, these springs 20 may be formed of a single piece of suitable metal bent into the-hollow rectangular shape illustrated, the long sides of'.tl1e rectangle forming the springs. The springs are then easily affixed to the base by means of a. clamp bar 22, and the terminal bracket 21 is easily afiixed to the springs by means of another clamp bar 23. Preferably, the two terminals 12 are duplicates, and each embodies a pair of clamp bars 25, radiating sheets 26 clamped between the bars, and a contact bar 27 mounted in the face of one of the clamp bars 25. The clamp bars 25 are preferably semicylindrical, their cylindrical faces being ad- The spring support is preferably con jacent each other; and the radiating sheets 26 are clamped between the cylindrical faces of these bars; the radiating sheets spreading out in fan configuration on each side as illustrated in Fig.' '1. These radiating sheets may be constructed or formed in any desired manner; but may preferably be formed eachof a single continuous strip of sheet "metal, such as copper, bent back and forth Figure 1 is a plan showing my complete a number oftimes and clamped tightly between the clamping bars 25. Each of the terminals'has a bolt 3Q, the bolt 17 being a.

continuation of one of the bolts 30. These bolts are securedin one of the clamp bars sheets 26 and through the other bar and then I through the support" 13 or the bracket 21;

a nut 31 serving to draw all the parts tightly together and clamp the heat radiating sheets tightly and solidly between the clamping bars. The heat radiating sheets are preferably of copper and the clamping bars are preferably of brass. The construction is such that heat generated at the gap is very readily conducted through the bars 25 to the radiating sheets 26 and radiated by them to the surrounding atmosphere. Y

The bars 25 have a long contact with the sheets 26; and there is a very large section of metal for the conduction of heat directly from the contact bars 27 to the radiating sheets 26. This feature of the elongate clamp bars having a long contact with the radiating sheets is an important one. The path traveled by heat from the contact bar to the radiating sheets is short. The clamp bar being of solid metal, being in close contact with the radiating sheets, the radiating sheetsbeing in close contact where they are clamped together, and the contact between the clamp bar and the radiatin sheets, and between the radiating sheets t eniselves, being long -all these features cause the ready and wide distributi '1 of heat over all the radiating surface. it will be noted that the radiating sheets are so placed that an upward draft of air is induced by heating the air between and around them.

The contact bars 27 are preferably made of silver; and their opposing contact faces are carefully dressed to be accurately parallel to each other. Once the apparatus is set up and these contact faces properly dressed the contact faces will always be maintained parallel to each other by the parallel action of the spring support 14. Being maintained in parallelism, the discharge across the gap is evenly distributed overthe contact surfaces and has no tendency to concentrate at any particular point. This fact, together with the fact that the generv ated heat is quickly carried away, and also that the contact faces are long and narrow allowing a comparatively free circulation of air in the gap, is conducive to indefinite life of the contact pieces. There is no tendency to overheat the metal of the contact pieces and there is no tendency to heat the contact pieces any more atone point than at another. The temperature of the whole apparatus is kept, low at all times; and the total result is that my spark gap apparatus with reasonable care, has an indefinite life even when used for long periods with very heavy currents.

duplicateterminalsinounted to be relatively movable to and from each other, each emthe bars, and an elongate contact'bar mount" ed upon one of the clamp bars presenting thin elongate edge away from the clamp 3. In a spark gap apparatus, a terminal embodying a pan of parallel semi-cylindrical metal clamp bars placed with their flat faces outwardly, heat radiating sheets clamped tightly between the bars and spreading out in fan configuration on each side, and an elongate contact bar set in the flat faceof one of the clamp bars presenting a thin elongate edge away from the clamp bar.

4. A spark gap apparatus, comprising two duplicate terminals arranged opposing each other, each terminal embodying a pair of parallel metal clamp bars, heat radiating sheets clamped between the bars, and an elongate contact bar mounted upon one of the clamp bars presenting a thin elongate edge away from the clamp bar, against the contact bar of the other terminal, and means for supporting said terminal so that one each other, heat radiating sheets clamped tightly between the bars and spreading out in fan configuration on each side, and an elongate contact bar set in the flat face of one of the clamp bars presenting a thin con.- v

tact edge away from the clamp bar toward the contact bar of the other terminal, and

means for supporting said terminals so that one may be moved to and from the other keeping the contact face of the contact bars parallel to each other.

6. A spark gap apparatus, comprising two duplicate terminals arranged opposing each other, each terminal embodying a pair of semi-cylindrical metal clamp bars placed with their flat faces outwardly away from each other, heat radiating sheets clamped tightly between the bars and spreading out in fan configuration on each side, and an elongate contact bar set in the fiat face of one of the clamp bars presenting a thin contact edge away from the clamp bar toward the contact bar of the other terminal, a rigid support for one of the terminals, and a spring support for the other terminal embodying a pair of spaced parallel flat springs. H

7. In a spark gap apparatus, a base, a in Witness that I claim the foregoing I rigid support thereon, a terminal on said have hereunto subscribed my name this 10th 10 rigid support, a spring suppert and. a terday of November 1914-. minal thereon opposing the first mentioned B'termin'aI, said spring support embodying a L pair of spaced parallel flat springs of equal "Witnesses:

' length having one end secured to the base James T. BARKELEW,

and the other end supporting the terminal ELwoon H. BARKELEW.

Copies of this patent may be obtaineci for five cents each, by addressing; the Commissioner of Patents,

Washington, D. G. 

